1. Field of the Invention
The invention relates generally to the field of support structures for immature trees. More particularly, the invention pertains to a pole or shaft support for trees which is adjustable in height. The shaft includes a ground-engaging helical screw on its lower end and a tree-engaging fastening arm on its upper end or along its length.
2. Description of Prior Art
The prior art teaches a number of devices for temporarily supporting young trees until they are firmly rooted in the ground and self-supporting. For example, U.S. Pat. No. 5,921,035 to Kempf (the xe2x80x9c""035 Patentxe2x80x9d) discloses a Lockable Screw Post Apparatus having helical coils wrapped around its lower end, and a lockable ground-engaging member parallel to the shaft of the apparatus. The device of the ""035 Patent is designed primarily to suspend objects such as a real estate sign, but it may be adapted for use in supporting young trees.
However, the device of the ""035 Patent has several drawbacks when employed as a tree support. For example, once implanted, the Kempf device is not adjustable in height. The disclosed device has no fastening mechanism for attachment to a tree. Further, the ground-engaging helical coils are not particularly well adapted to penetrate hard soils. Finally, the lockable ground-engaging member extends into the ground parallel to the shaft, and thus may not adequately prevent unwanted removal of the shaft from the ground by upward pulling forces.
U.S. Pat. No. 6,299,125 to Zayeratabat (the xe2x80x9c""125 Patentxe2x80x9d) discloses a Tree Support Apparatus having a pointed lower end, telescoping stakes, and means for attaching the apparatus to the trunk or stem of a plant or small tree. The apparatus of the ""125 Patent also has certain disadvantages. For example, the pointed tip of the lower end will not easily penetrate hardpan or rocky soils. And, the means for attaching the stake to the tree is overly complicated in both assembly and use.
The Reddy Stake(trademark) System installation guide, disclosed in the accompanying Information Disclosure Statement, also shows a device for supporting trees. The Reddy Stake(trademark) device includes an anchoring bar to limit rotational movement of the device when implanted in the ground. The device further includes a T-bar extending from the support pole. Rubber tubing and tie-wraps are used to secure the tree to the T-bar. However, the device is not adjustable in height once implanted in the ground, and the pointed tip of the lower end will not easily penetrate hardpan or rocky soils. Further, the T-bar and rubber tubing connection system is unnecessarily complicated in both assembly and use. Another disadvantage of the device is that the height of the ground-engaging anchoring bar is not adjustable with respect to the support pole. Also, although the T-bar may be adjusted vertically on the pole, any length of the pole extending above the T-bar can potentially gouge and injure the tree. Further, the ground-engaging helical screw coils, at the lower end of the device, are not particularly well adapted to penetrate hard soils.
Thus, the need exists for a simple, efficient, reusable, lightweight, robust and durable apparatus for supporting immature trees in underlying soils of varying hardness. The present invention overcomes the disadvantages of known prior art devices and satisfies the above-recited needs.
The present invention includes a height-adjustable vertical shaft, having a specially-adapted lower end for effective penetration of hard ground. It also has a simple, rigid fastening arm with a ratchet mechanism and an adjustable strap to couple the shaft to the tree. In addition, the invention includes a shaft-anchoring device which penetrates the ground at such an angle so as to prevent both rotational and vertical movement of the shaft.
Therefore, it is an object of the present invention to provide a simple, economical, and reusable device to support dependent, immature trees.
Another object is to provide a height-adjustable tree support that efficiently penetrates and engages a variety of soils.
Still another object is to provide a tree support having an adjustable fastening arm for connecting the tree and the support.
An additional object is to provide a height-adjustable tree support having an adjustable fastening arm, which is attached to the top of the tree support, for connecting the tree and the support.
Yet another object is to provide a tree support including an adjustable-height ground anchor attached to the support shaft to resist rotational and vertical movement of the shaft.
These and other objects of the invention will be explained more fully in the detailed description of the preferred embodiment to follow.
The present invention provides an apparatus for supporting the trunk of an immature tree, until the tree is sufficiently large and well-rooted to support itself. The apparatus includes an elongated, vertical shaft that is adjustable in length. A lower end of the shaft is fitted with a helical screw, specially adapted for rotational penetration into the ground. The helical screw has a conical tip, followed by a spiral rib section. The rib section resembles the threaded portion of a screw, but is different in that it includes a spiral channel flanked by shelves extending between the channel and the walls of the spiral rib. The combination of the rib and the channel is effective both to penetrate the ground and to remove dislodged soil from the path of the helical screw.
The apparatus also has a rigid fastening arm extending outwardly, in perpendicular fashion, from the shaft. An outer end of the fastening arm has a flexible strap with a free end. The fastening arm has a ratchet mechanism contained within it to secure the free end of the flexible strap. Extending the strap around the tree forms a loop of desired dimension to restrain the tree trunk from excessive lateral excursions.
The apparatus is also provided with an anchoring device to prevent movement of the shaft after it is implanted in the ground. The anchoring device includes an anchoring bracket that is slid down the shaft to the point where it enters the ground. Then, the anchoring bracket is locked to the shaft. The anchoring bracket includes a flange and a collar. The flange has an aperture to receive a ground-engaging rod. The aperture has an axis oriented at an angle not perpendicular to the longitudinal axis of the shaft. Thus, when implanted in the ground through the aperture, the rod is disposed at an angle effective to prevent both rotational movement and vertical movement of the shaft.
Yet another feature of the invention is a lever fitting attached to the shaft to facilitate rotational installation of the shaft into the ground. The lever fitting includes a bore for insertion of a lever arm. The bore has an axis that is laterally displaced and perpendicular to the longitudinal axis of the shaft. Rotational movement of the end of the lever arm thereby provides mechanically-advantaged rotational forces to the shaft and the helical screw on its lower end.